The document discusses various data structures and functions related to network packet processing in the Linux kernel socket layer. It describes the sk_buff structure that is used to pass packets between layers. It also explains the net_device structure that represents a network interface in the kernel. When a packet is received, the interrupt handler will raise a soft IRQ for processing. The packet will then traverse various protocol layers like IP and TCP to be eventually delivered to a socket and read by a userspace application.
Agenda:
In this session, Shmulik Ladkani discusses the kernel's net_device abstraction, its interfaces, and how net-devices interact with the network stack. The talk covers many of the software network devices that exist in the Linux kernel, the functionalities they provide and some interesting use cases.
Speaker:
Shmulik Ladkani is a Tech Lead at Ravello Systems.
Shmulik started his career at Jungo (acquired by NDS/Cisco) implementing residential gateway software, focusing on embedded Linux, Linux kernel, networking and hardware/software integration.
51966 coffees and billions of forwarded packets later, with millions of homes running his software, Shmulik left his position as Jungo’s lead architect and joined Ravello Systems (acquired by Oracle) as tech lead, developing a virtual data center as a cloud service. He's now focused around virtualization systems, network virtualization and SDN.
SOSCON 2019.10.17
What are the methods for packet processing on Linux? And how fast are each packet processing methods? In this presentation, we will learn how to handle packets on Linux (User space, socket filter, netfilter, tc), and compare performance with analysis of where each packet processing is done in the network stack (hook point). Also, we will discuss packet processing using XDP, an in-kernel fast-path recently added to the Linux kernel. eXpress Data Path (XDP) is a high-performance programmable network data-path within the Linux kernel. The XDP is located at the lowest level of access through SW in the network stack, the point at which driver receives the packet. By using the eBPF infrastructure at this hook point, the network stack can be expanded without modifying the kernel.
Daniel T. Lee (Hoyeon Lee)
@danieltimlee
Daniel T. Lee currently works as Software Engineer at Kosslab and contributing to Linux kernel BPF project. He has interest in cloud, Linux networking, and tracing technologies, and likes to analyze the kernel's internal using BPF technology.
LinuxCon 2015 Linux Kernel Networking WalkthroughThomas Graf
This presentation features a walk through the Linux kernel networking stack for users and developers. It will cover insights into both, existing essential networking features and recent developments and will show how to use them properly. Our starting point is the network card driver as it feeds a packet into the stack. We will follow the packet as it traverses through various subsystems such as packet filtering, routing, protocol stacks, and the socket layer. We will pause here and there to look into concepts such as networking namespaces, segmentation offloading, TCP small queues, and low latency polling and will discuss how to configure them.
In this talk Jiří Pírko discusses the design and evolution of the VLAN implementation in Linux, the challenges and pitfalls as well as hardware acceleration and alternative implementations.
Jiří Pírko is a major contributor to kernel networking and the creator of libteam for link aggregation.
Agenda:
In this session, Shmulik Ladkani discusses the kernel's net_device abstraction, its interfaces, and how net-devices interact with the network stack. The talk covers many of the software network devices that exist in the Linux kernel, the functionalities they provide and some interesting use cases.
Speaker:
Shmulik Ladkani is a Tech Lead at Ravello Systems.
Shmulik started his career at Jungo (acquired by NDS/Cisco) implementing residential gateway software, focusing on embedded Linux, Linux kernel, networking and hardware/software integration.
51966 coffees and billions of forwarded packets later, with millions of homes running his software, Shmulik left his position as Jungo’s lead architect and joined Ravello Systems (acquired by Oracle) as tech lead, developing a virtual data center as a cloud service. He's now focused around virtualization systems, network virtualization and SDN.
SOSCON 2019.10.17
What are the methods for packet processing on Linux? And how fast are each packet processing methods? In this presentation, we will learn how to handle packets on Linux (User space, socket filter, netfilter, tc), and compare performance with analysis of where each packet processing is done in the network stack (hook point). Also, we will discuss packet processing using XDP, an in-kernel fast-path recently added to the Linux kernel. eXpress Data Path (XDP) is a high-performance programmable network data-path within the Linux kernel. The XDP is located at the lowest level of access through SW in the network stack, the point at which driver receives the packet. By using the eBPF infrastructure at this hook point, the network stack can be expanded without modifying the kernel.
Daniel T. Lee (Hoyeon Lee)
@danieltimlee
Daniel T. Lee currently works as Software Engineer at Kosslab and contributing to Linux kernel BPF project. He has interest in cloud, Linux networking, and tracing technologies, and likes to analyze the kernel's internal using BPF technology.
LinuxCon 2015 Linux Kernel Networking WalkthroughThomas Graf
This presentation features a walk through the Linux kernel networking stack for users and developers. It will cover insights into both, existing essential networking features and recent developments and will show how to use them properly. Our starting point is the network card driver as it feeds a packet into the stack. We will follow the packet as it traverses through various subsystems such as packet filtering, routing, protocol stacks, and the socket layer. We will pause here and there to look into concepts such as networking namespaces, segmentation offloading, TCP small queues, and low latency polling and will discuss how to configure them.
In this talk Jiří Pírko discusses the design and evolution of the VLAN implementation in Linux, the challenges and pitfalls as well as hardware acceleration and alternative implementations.
Jiří Pírko is a major contributor to kernel networking and the creator of libteam for link aggregation.
The Linux Block Layer - Built for Fast StorageKernel TLV
The arrival of flash storage introduced a radical change in performance profiles of direct attached devices. At the time, it was obvious that Linux I/O stack needed to be redesigned in order to support devices capable of millions of IOPs, and with extremely low latency.
In this talk we revisit the changes the Linux block layer in the
last decade or so, that made it what it is today - a performant, scalable, robust and NUMA-aware subsystem. In addition, we cover the new NVMe over Fabrics support in Linux.
Sagi Grimberg
Sagi is Principal Architect and co-founder at LightBits Labs.
netfilter is a framework provided by the Linux kernel that allows various networking-related operations to be implemented in the form of customized handlers.
iptables is a user-space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall (implemented as different netfilter modules) and the chains and rules it stores.
Many systems use iptables/netfilter, Linux's native packet filtering/mangling framework since Linux 2.4, be it home routers or sophisticated cloud network stacks.
In this session, we will talk about the netfilter framework and its facilities, explain how basic filtering and mangling use-cases are implemented using iptables, and introduce some less common but powerful extensions of iptables.
Shmulik Ladkani, Chief Architect at Nsof Networks.
Long time network veteran and kernel geek.
Shmulik started his career at Jungo (acquired by NDS/Cisco) implementing residential gateway software, focusing on embedded Linux, Linux kernel, networking and hardware/software integration.
Some billions of forwarded packets later, Shmulik left his position as Jungo's lead architect and joined Ravello Systems (acquired by Oracle) as tech lead, developing a virtual data center as a cloud-based service, focusing around virtualization systems, network virtualization and SDN.
Recently he co-founded Nsof Networks, where he's been busy architecting network infrastructure as a cloud-based service, gazing at internet routes in astonishment, and playing the chkuku.
Linux offers an extensive selection of programmable and configurable networking components from traditional bridges, encryption, to container optimized layer 2/3 devices, link aggregation, tunneling, several classification and filtering languages all the way up to full SDN components. This talk will provide an overview of many Linux networking components covering the Linux bridge, IPVLAN, MACVLAN, MACVTAP, Bonding/Team, OVS, classification & queueing, tunnel types, hidden routing tricks, IPSec, VTI, VRF and many others.
Talk by Brendan Gregg for USENIX LISA 2019: Linux Systems Performance. Abstract: "
Systems performance is an effective discipline for performance analysis and tuning, and can help you find performance wins for your applications and the kernel. However, most of us are not performance or kernel engineers, and have limited time to study this topic. This talk summarizes the topic for everyone, touring six important areas of Linux systems performance: observability tools, methodologies, benchmarking, profiling, tracing, and tuning. Included are recipes for Linux performance analysis and tuning (using vmstat, mpstat, iostat, etc), overviews of complex areas including profiling (perf_events) and tracing (Ftrace, bcc/BPF, and bpftrace/BPF), and much advice about what is and isn't important to learn. This talk is aimed at everyone: developers, operations, sysadmins, etc, and in any environment running Linux, bare metal or the cloud."
DockerCon 2017 - Cilium - Network and Application Security with BPF and XDPThomas Graf
This talk will start with a deep dive and hands on examples of BPF, possibly the most promising low level technology to address challenges in application and network security, tracing, and visibility. We will discuss how BPF evolved from a simple bytecode language to filter raw sockets for tcpdump to the a JITable virtual machine capable of universally extending and instrumenting both the Linux kernel and user space applications. The introduction is followed by a concrete example of how the Cilium open source project applies BPF to solve networking, security, and load balancing for highly distributed applications. We will discuss and demonstrate how Cilium with the help of BPF can be combined with distributed system orchestration such as Docker to simplify security, operations, and troubleshooting of distributed applications.
High-Performance Networking Using eBPF, XDP, and io_uringScyllaDB
In the networking world there are a number of ways to increase performance over naive use of basic Berkeley sockets. These techniques have ranged from polling blocking sockets, non-blocking sockets controlled by Epoll, all the way through completely bypassing the Linux kernel for maximum network performance where you talk directly to the network interface card by using something like DPDK or Netmap. All these tools have their place, and generally occupy a space from convenience to performance. But in recent years, that landscape has changed massively.. The tools available to the average Linux systems developer have improved from the creation of io_uring, to the expansion of bpf from a simple filtering language to a full-on programming environment embedded directly in the kernel. Along with that came something called XDP (express datapath). This was Linux kernel's answer to kernel-bypass networking. AF_XDP is the new socket type created by this feature, and generally works very similarly to something like DPDK. History lessons out of the way, this talk will look into, and discuss the merits of this technology, it's place in the broader ecosystem and how it can be used to attain the highest level of performance possible. This talk will dive into crucial details, such as how AF_XDP works, how it can be integrated into a larger system and finally more advanced topics such as request sharding/load balancing. There will be detailed look at the design of AF_XDP, the eBpf code used, as well as the userspace code required to drive it all. It will also include performance numbers from this setup compared to regular kernel networking. And most importantly how to put all this together to handle as much data as possible on a single modern multi-core system.
This presentation features a walk through the Linux kernel networking stack covering the essentials and recent developments a developer needs to know. Our starting point is the network card driver as it feeds a packet into the stack. We will follow the packet as it traverses through various subsystems such as packet filtering, routing, protocol stacks, and the socket layer. We will pause here and there to look into concepts such as segmentation offloading, TCP small queues, and low latency polling. We will cover APIs exposed by the kernel that go beyond use of write()/read() on sockets and will look into how they are implemented on the kernel side.
This presentation includes basic information related to sockets ,socket-buffer,cliet-server programs and relationship between them
The files included in the ppt for the variables are taken from linux-2.6.10.
In case of any queriers.
contact souravpunoriyar@gmail.com
Netronome's half-day tutorial on host data plane acceleration at ACM SIGCOMM 2018 introduced attendees to models for host data plane acceleration and provided an in-depth understanding of SmartNIC deployment models at hyperscale cloud vendors and telecom service providers.
Presenter Bios
Jakub Kicinski is a long term Linux kernel contributor, who has been leading the kernel team at Netronome for the last two years. Jakub’s major contributions include the creation of BPF hardware offload mechanisms in the kernel and bpftool user space utility, as well as work on the Linux kernel side of OVS offload.
David Beckett is a Software Engineer at Netronome with a strong technical background of computer networks including academic research with DDoS. David has expertise in the areas of Linux architecture and computer programming. David has a Masters Degree in Electrical, Electronic Engineering at Queen’s University Belfast and continues as a PhD student studying Emerging Application Layer DDoS threats.
Tutorial: Using GoBGP as an IXP connecting routerShu Sugimoto
- Show you how GoBGP can be used as a software router in conjunction with quagga
- (Tutorial) Walk through the setup of IXP connecting router using GoBGP
The first version of eBPF hardware offload was merged into the Linux kernel in October 2016 and became part of Linux v4.9. For the last two years the project has been growing and evolving to integrate more closely with the core kernel infrastructure and enable more advanced use cases. This talk will explain the internals of the kernel architecture of the offload and how it allows seamless execution of unmodified eBPF datapaths in HW.
BPF of Berkeley Packet Filter mechanism was first introduced in linux in 1997 in version 2.1.75. It has seen a number of extensions of the years. Recently in versions 3.15 - 3.19 it received a major overhaul which drastically expanded it's applicability. This talk will cover how the instruction set looks today and why. It's architecture, capabilities, interface, just-in-time compilers. We will also talk about how it's being used in different areas of the kernel like tracing and networking and future plans.
I am Bernard. I am a C Assignment Expert at programminghomeworkhelp.com. I hold a Ph.D. in Programming from, University of Leeds, UK. I have been helping students with their homework for the past 9 years. I solve assignments related to C Programming.
Visit programminghomeworkhelp.com or email support@programminghomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with C Programming Assignments.
The Linux Block Layer - Built for Fast StorageKernel TLV
The arrival of flash storage introduced a radical change in performance profiles of direct attached devices. At the time, it was obvious that Linux I/O stack needed to be redesigned in order to support devices capable of millions of IOPs, and with extremely low latency.
In this talk we revisit the changes the Linux block layer in the
last decade or so, that made it what it is today - a performant, scalable, robust and NUMA-aware subsystem. In addition, we cover the new NVMe over Fabrics support in Linux.
Sagi Grimberg
Sagi is Principal Architect and co-founder at LightBits Labs.
netfilter is a framework provided by the Linux kernel that allows various networking-related operations to be implemented in the form of customized handlers.
iptables is a user-space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall (implemented as different netfilter modules) and the chains and rules it stores.
Many systems use iptables/netfilter, Linux's native packet filtering/mangling framework since Linux 2.4, be it home routers or sophisticated cloud network stacks.
In this session, we will talk about the netfilter framework and its facilities, explain how basic filtering and mangling use-cases are implemented using iptables, and introduce some less common but powerful extensions of iptables.
Shmulik Ladkani, Chief Architect at Nsof Networks.
Long time network veteran and kernel geek.
Shmulik started his career at Jungo (acquired by NDS/Cisco) implementing residential gateway software, focusing on embedded Linux, Linux kernel, networking and hardware/software integration.
Some billions of forwarded packets later, Shmulik left his position as Jungo's lead architect and joined Ravello Systems (acquired by Oracle) as tech lead, developing a virtual data center as a cloud-based service, focusing around virtualization systems, network virtualization and SDN.
Recently he co-founded Nsof Networks, where he's been busy architecting network infrastructure as a cloud-based service, gazing at internet routes in astonishment, and playing the chkuku.
Linux offers an extensive selection of programmable and configurable networking components from traditional bridges, encryption, to container optimized layer 2/3 devices, link aggregation, tunneling, several classification and filtering languages all the way up to full SDN components. This talk will provide an overview of many Linux networking components covering the Linux bridge, IPVLAN, MACVLAN, MACVTAP, Bonding/Team, OVS, classification & queueing, tunnel types, hidden routing tricks, IPSec, VTI, VRF and many others.
Talk by Brendan Gregg for USENIX LISA 2019: Linux Systems Performance. Abstract: "
Systems performance is an effective discipline for performance analysis and tuning, and can help you find performance wins for your applications and the kernel. However, most of us are not performance or kernel engineers, and have limited time to study this topic. This talk summarizes the topic for everyone, touring six important areas of Linux systems performance: observability tools, methodologies, benchmarking, profiling, tracing, and tuning. Included are recipes for Linux performance analysis and tuning (using vmstat, mpstat, iostat, etc), overviews of complex areas including profiling (perf_events) and tracing (Ftrace, bcc/BPF, and bpftrace/BPF), and much advice about what is and isn't important to learn. This talk is aimed at everyone: developers, operations, sysadmins, etc, and in any environment running Linux, bare metal or the cloud."
DockerCon 2017 - Cilium - Network and Application Security with BPF and XDPThomas Graf
This talk will start with a deep dive and hands on examples of BPF, possibly the most promising low level technology to address challenges in application and network security, tracing, and visibility. We will discuss how BPF evolved from a simple bytecode language to filter raw sockets for tcpdump to the a JITable virtual machine capable of universally extending and instrumenting both the Linux kernel and user space applications. The introduction is followed by a concrete example of how the Cilium open source project applies BPF to solve networking, security, and load balancing for highly distributed applications. We will discuss and demonstrate how Cilium with the help of BPF can be combined with distributed system orchestration such as Docker to simplify security, operations, and troubleshooting of distributed applications.
High-Performance Networking Using eBPF, XDP, and io_uringScyllaDB
In the networking world there are a number of ways to increase performance over naive use of basic Berkeley sockets. These techniques have ranged from polling blocking sockets, non-blocking sockets controlled by Epoll, all the way through completely bypassing the Linux kernel for maximum network performance where you talk directly to the network interface card by using something like DPDK or Netmap. All these tools have their place, and generally occupy a space from convenience to performance. But in recent years, that landscape has changed massively.. The tools available to the average Linux systems developer have improved from the creation of io_uring, to the expansion of bpf from a simple filtering language to a full-on programming environment embedded directly in the kernel. Along with that came something called XDP (express datapath). This was Linux kernel's answer to kernel-bypass networking. AF_XDP is the new socket type created by this feature, and generally works very similarly to something like DPDK. History lessons out of the way, this talk will look into, and discuss the merits of this technology, it's place in the broader ecosystem and how it can be used to attain the highest level of performance possible. This talk will dive into crucial details, such as how AF_XDP works, how it can be integrated into a larger system and finally more advanced topics such as request sharding/load balancing. There will be detailed look at the design of AF_XDP, the eBpf code used, as well as the userspace code required to drive it all. It will also include performance numbers from this setup compared to regular kernel networking. And most importantly how to put all this together to handle as much data as possible on a single modern multi-core system.
This presentation features a walk through the Linux kernel networking stack covering the essentials and recent developments a developer needs to know. Our starting point is the network card driver as it feeds a packet into the stack. We will follow the packet as it traverses through various subsystems such as packet filtering, routing, protocol stacks, and the socket layer. We will pause here and there to look into concepts such as segmentation offloading, TCP small queues, and low latency polling. We will cover APIs exposed by the kernel that go beyond use of write()/read() on sockets and will look into how they are implemented on the kernel side.
This presentation includes basic information related to sockets ,socket-buffer,cliet-server programs and relationship between them
The files included in the ppt for the variables are taken from linux-2.6.10.
In case of any queriers.
contact souravpunoriyar@gmail.com
Netronome's half-day tutorial on host data plane acceleration at ACM SIGCOMM 2018 introduced attendees to models for host data plane acceleration and provided an in-depth understanding of SmartNIC deployment models at hyperscale cloud vendors and telecom service providers.
Presenter Bios
Jakub Kicinski is a long term Linux kernel contributor, who has been leading the kernel team at Netronome for the last two years. Jakub’s major contributions include the creation of BPF hardware offload mechanisms in the kernel and bpftool user space utility, as well as work on the Linux kernel side of OVS offload.
David Beckett is a Software Engineer at Netronome with a strong technical background of computer networks including academic research with DDoS. David has expertise in the areas of Linux architecture and computer programming. David has a Masters Degree in Electrical, Electronic Engineering at Queen’s University Belfast and continues as a PhD student studying Emerging Application Layer DDoS threats.
Tutorial: Using GoBGP as an IXP connecting routerShu Sugimoto
- Show you how GoBGP can be used as a software router in conjunction with quagga
- (Tutorial) Walk through the setup of IXP connecting router using GoBGP
The first version of eBPF hardware offload was merged into the Linux kernel in October 2016 and became part of Linux v4.9. For the last two years the project has been growing and evolving to integrate more closely with the core kernel infrastructure and enable more advanced use cases. This talk will explain the internals of the kernel architecture of the offload and how it allows seamless execution of unmodified eBPF datapaths in HW.
BPF of Berkeley Packet Filter mechanism was first introduced in linux in 1997 in version 2.1.75. It has seen a number of extensions of the years. Recently in versions 3.15 - 3.19 it received a major overhaul which drastically expanded it's applicability. This talk will cover how the instruction set looks today and why. It's architecture, capabilities, interface, just-in-time compilers. We will also talk about how it's being used in different areas of the kernel like tracing and networking and future plans.
I am Bernard. I am a C Assignment Expert at programminghomeworkhelp.com. I hold a Ph.D. in Programming from, University of Leeds, UK. I have been helping students with their homework for the past 9 years. I solve assignments related to C Programming.
Visit programminghomeworkhelp.com or email support@programminghomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with C Programming Assignments.
Have you ever heard of FreeBSD? Probably.
Have you ever interacted with its kernel? Probably not.
In this talk, Gili Yankovitch (nyxsecuritysolutions.com) will talk about the FreeBSD operating system, its network stack and how to write network drivers for it.
The talk will cover the following topics:
* Kernel/User interation in FreeBSD
* The FreeBSD Network Stack
* Network Buffers API
* L2 and L3 Hooking
LAS16-300: Mini Conference 2 Cortex-M Software - Device ConfigurationLinaro
LAS16-300: Mini Conference 2 RTOS-Zephyr - Device Configuration
Speakers: Andy Gross
Date: September 28, 2016
★ Session Description ★
SoC Vendors, board vendors, software middle layers, scripting languages, etc all need to have access to system configuration information (pin muxes, what sensors are on a system, what amount of memory, flash, etc, etc). We need a means to convey this in a vendor neutral mechanism but also one that is friendly for Cortex-M/constrained footprint devices. This session will be to discuss the topic, how its done today, what kinda tooling might exist from different vendors, what we could utilize (device tree) and what issues that creates.
★ Resources ★
Etherpad: pad.linaro.org/p/las16-300
Presentations & Videos: http://connect.linaro.org/resource/las16/las16-300/
★ Event Details ★
Linaro Connect Las Vegas 2016 – #LAS16
September 26-30, 2016
http://www.linaro.org
http://connect.linaro.org
Process Address Space: The way to create virtual address (page table) of user...Adrian Huang
Process Address Space: The way to create virtual address (page table) of userspace application.
Note: When you view the the slide deck via web browser, the screenshots may be blurred. You can download and view them offline (Screenshots are clear).
Kernel Recipes 2014 - What I’m forgetting when designing a new userspace inte...Anne Nicolas
When designing a new interface between kernel and userspace, say a new ioctl, a new character device or a new syscall, I’m forgetting some basic issues and/or corner cases.
This talk is about such pitfalls and how to address them.
Yann Droneaud, OPTEYA
Similar to The TCP/IP Stack in the Linux Kernel (20)
Tuning Flink Clusters for stability and efficiencyDivye Kapoor
Pinterest tuned their Apache Flink clusters to reduce cost by over 50%. The slide deck was presented at Flink Forward 2023 to an audience of software developers at Square (Block), Bloomberg, Ververica, Alibaba and more.
The corresponding blog post is at https://medium.com/pinterest-engineering/tuning-flink-clusters-for-stability-and-efficiency-50d3d50384ed
A particle filter based scheme for indoor tracking on an Android SmartphoneDivye Kapoor
A particle filter based scheme for indoor tracking on an Android Smartphone.
These are slides accompanying the Masters thesis of the same name presented as part of the graduating requirements at IIT Roorkee. They detail a sensor fusion based approach taken to indoor tracking on smartphones.
The Linux Kernel Implementation of Pipes and FIFOsDivye Kapoor
A walkthrough of the code structure used in the linux kernel to implement pipes and FIFOs.
This was presented to a Senior level class at the Indian Institute of Technology, Roorkee.
These are the questions asked in the prelims round of Cybermania - a computer quiz held at Loyola School, Jamshedpur, India. The quiz was for students of standard 6 to 10.
If you have any doubts or further questions, contact the quizmaster at Twitter: @divyekapoor or on Google+ at http://gplus.to/divyekapoor
I'll be happy to share the slides with you if you ask me politely on any of these social networks. :)
These are the questions asked in the main round of Cybermania - a computer quiz held at Loyola School, Jamshedpur, India. The quiz was for students of standard 6 to 10.
If you have any doubts or further questions, contact the quizmaster at Twitter: @divyekapoor or on Google+ at http://gplus.to/divyekapoor
I'll be happy to share the slides with you if you ask me politely on any of these social networks. :)
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
3. It is the software layer in the kernel that provides a
uniform filesystem interface to userspace programs
It provides an abstraction within the kernel that allows
for transparent working with a variety of filesystems.
Thus it allows many different filesystem
implementations to coexist freely
Each socket is implemented as a “file” mounted on
the sockfs filesystem.
file->private points to the socket information.
4. Inodes provide a method to access the actual
data blocks allocated to a file. For sockets, they
provide buffer space which can be used to hold
socket specific data.
struct inode
Every file is represented in the kernel as an
object of the file structure. It requires an inode
provided to it.
struct file
7. User Space
Socket, bind, listen, connect, send, recv, write, read etc.
Socket Functions (Kernel)
sys_socket, sys_bind, sys_listen, sys_connect etc. in socket.c
TCP/IP Layer Functions
inet_create, tcp_v4_connect, tcp_sendmsg, tcp_recvmsg
Ethernet Device Layer
dev_hard_start_xmit
8. Sys_socket()
Sock_create() Sock_map_fd()
Allocate a socket object
(internally an inode
Associated with a file object)
Locate the family requested and
call the create function for that
family
Inet_create()
Lower layer initialization
Sock_alloc_fd()
Allocate a file descriptor
Sock_attach_fd()
Fd_install()
15. Defined in <include/linux/skbuff.h>
used by every network layer (except the physical layer)
fields of the structure change as it is passed from one layer to another
i.e., fields are layer dependent.
16. struct sk_buff {
... ... ...
#ifdef CONFIG_NET_SCHED
_ _u32 tc_index;
#ifdef CONFIG_NET_CLS_ACT
_ _u32 tc_verd;
_ _u32 tc_classid;
#endif
#endif
}
sk_buff is peppered with C preprocessor #ifdef directives.
CONFIG_NET_SCHED symbol should be defined at compile time for the
structure to have the element tc_index.
enabled with some version of make config by an administrator.
17. The kernel maintains all sk_buff structures in a doubly linked list.
struct sk_buff_head {/* only the head of the list */
/*These two members must be first. */
struct sk_buff * next;
struct sk_buff * prev;
_ _u32 qlen;
spinlock_t lock;/* atomicity in accessing a sk_buff list. */
};
19. struct sock * sk
sock data structure of the socket that owns this buffer
unsigned int len
includes both the data in the main buffer (i.e., the one pointed to by head)
and the data in the fragments
unsigned int data_len
unlike len, data_len accounts only for the size of the data in the fragments.
unsigned int truesize
skb->truesize = size + sizeof(struct sk_buff);
atomic_t users
reference count, or the number of entities using this sk_buff buffer
atomic_inc and atomic_dec
20. struct sock * sk
sock data structure of the socket that owns this buffer
unsigned int len
includes both the data in the main buffer (i.e., the one pointed to by
head) and the data in the fragments
unsigned int data_len
unlike len, data_len accounts only for the size of the data in the fragments.
unsigned int truesize
skb->truesize = size + sizeof(struct sk_buff);
atomic_t users
reference count, or the number of entities using this sk_buff buffer
atomic_inc and atomic_dec
21. struct sock * sk
sock data structure of the socket that owns this buffer
unsigned int len
includes both the data in the main buffer (i.e., the one pointed to by head)
and the data in the fragments
unsigned int data_len
unlike len, data_len accounts only for the size of the data in the
fragments.
unsigned int truesize
skb->truesize = size + sizeof(struct sk_buff);
atomic_t users
reference count, or the number of entities using this sk_buff buffer
atomic_inc and atomic_dec
22. struct sock * sk
sock data structure of the socket that owns this buffer
unsigned int len
includes both the data in the main buffer (i.e., the one pointed to by head)
and the data in the fragments
unsigned int data_len
unlike len, data_len accounts only for the size of the data in the fragments.
unsigned int truesize
skb->truesize = size + sizeof(struct sk_buff);
atomic_t users
reference count, or the number of entities using this sk_buff buffer
atomic_inc and atomic_dec
23. struct sock * sk
sock data structure of the socket that owns this buffer
unsigned int len
includes both the data in the main buffer (i.e., the one pointed to by head)
and the data in the fragments
unsigned int data_len
unlike len, data_len accounts only for the size of the data in the fragments.
unsigned int truesize
skb->truesize = size + sizeof(struct sk_buff);
atomic_t users
reference count, or the number of entities using this sk_buff buffer
atomic_inc() and atomic_dec()
25. struct net_device *dev
represents the receiving interface or the to be transmitted device(or
interface) corresponding to the packet.
usually represents the virtual device’s(representation of all devices
grouped) net_device structure.
Pointers to protocol headers.
sk_buff_data_t transport_header;
sk_buff_data_t network_header;
sk_buff_data_t mac_header;
32. defined in <net/core/skbuff.c>
struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
int fclone, int node)
…
size = SKB_DATA_ALIGN(size);
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
…
33. struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
unsigned int length, gfp_t gfp_mask)
The buffer allocation function meant for use by device drivers
Executed in interrupt mode
Freeing memory: kfree_skb and dev_kfree_skb
Release buffer back to the buffer-pool.
Buffer released only when skb_users counter is 1. If not, the counter is
decremented.
46. Defined in <include/linux/netdevice.h>
stores all information specifically regarding a network device
one such structure for each device, both real ones (such as Ethernet
NICs) and virtual ones
Network devices can be classified into types such as Ethernet cards and
Token Ring cards
Each type may come in several models.
Model specific parameters are initialized by device driver software.
Parameters common for different models are initiated by kernel.
47. struct net_device{
char name[IFNAMSIZ];
int ifindex;
/* device name hash chain, ex: eth0 */
struct hlist_node name_hlist;
unsigned long mem_end;/* shared mem end */
unsigned long mem_start; /* shared mem start */
unsigned long base_addr; /* device I/O address */
unsigned int irq; /* device IRQ number*/
unsigned char if_port; /* Selectable AUI,TP,..*/
unsigned char dma; /* DMA channel */
…
48. struct net_device{
char name[IFNAMSIZ];
int ifindex;
/* device name hash chain, ex: eth0 */
struct hlist_node name_hlist;
unsigned long mem_end; /* shared mem end */
unsigned long mem_start; /* shared mem start */
unsigned long base_addr; /* device I/O address */
unsigned int irq; /* device IRQ number*/
unsigned char if_port; /* Selectable AUI,TP,..*/
unsigned char dma; /* DMA channel */
…
49. struct net_device{
char name[IFNAMSIZ];
int ifindex;
/* device name hash chain, ex: eth0 */
struct hlist_node name_hlist;
unsigned long mem_end;/* shared mem end */
unsigned long mem_start; /* shared mem start */
unsigned long base_addr; /* device I/O address */
unsigned int irq; /* device IRQ number*/
unsigned char if_port; /* Selectable AUI,TP,..*/
unsigned char dma; /* DMA channel
*/
50. struct net_device{
char name[IFNAMSIZ];
/* device name hash chain, ex: eth0 */
struct hlist_node name_hlist;
unsigned long mem_end;/* shared mem end */
unsigned long mem_start; /* shared mem start */
unsigned long base_addr; /* device I/O address */
unsigned int irq; /* device IRQ number*/
unsigned char if_port; /* Selectable AUI,TP,..*/
unsigned char dma; /* DMA channel */
unsigned short flags; /* interface flags (a la BSD) */
…
51. struct net_device{
char name[IFNAMSIZ];
/* device name hash chain, ex: eth0 */
struct hlist_node name_hlist;
unsigned long mem_end;/* shared mem end */
unsigned long mem_start; /* shared mem start */
unsigned long base_addr; /* device I/O address */
unsigned int irq; /* device IRQ number*/
unsigned char if_port; /* Selectable AUI,TP,..*/
unsigned char dma; /* DMA channel */
unsigned short flags; /* interface flags (a la BSD)*/
…
52. struct net_device{
char name[IFNAMSIZ];
/* device name hash chain, ex: eth0 */
struct hlist_node name_hlist;
unsigned long mem_end;/* shared mem end */
unsigned long mem_start; /* shared mem start */
unsigned long base_addr; /* device I/O address */
unsigned int irq; /* device IRQ number*/
unsigned char if_port; /* Selectable AUI,TP,..*/
unsigned char dma; /* DMA channel */
unsigned short flags; /* interface flags (a la BSD)*/
/* ex : IFF_UP || IFF_RUNNING || IFF_MULTICAST */
53. struct net_device{
…
unsigned mtu; /* interface MTU value */
unsigned short type; /* interface hardware type */
unsigned short hard_header_len; /* hardware hdr length */
unsigned char dev_addr[MAX_ADDR_LEN];
unsigned char addr_len; /* hardware address length */
unsigned char broadcast[MAX_ADDR_LEN];
unsigned int promiscuity;
…
54. struct net_device{
…
unsigned mtu; /* interface MTU value */
unsigned short type; /* interface hardware type*/
unsigned short hard_header_len; /* hardware hdr length */
unsigned char dev_addr[MAX_ADDR_LEN];
unsigned char addr_len; /* hardware address length */
unsigned char broadcast[MAX_ADDR_LEN];
unsigned int promiscuity;
…
55. struct net_device{
…
unsigned mtu; /* interface MTU value */
unsigned short type; /* interface hardware type */
unsigned short hard_header_len;/* hardware hdr length */
unsigned char dev_addr[MAX_ADDR_LEN];
unsigned char addr_len; /* hardware address length */
unsigned char broadcast[MAX_ADDR_LEN];
unsigned int promiscuity;
…
56. struct net_device{
…
unsigned mtu; /* interface MTU value */
unsigned short type; /* interface hardware type */
unsigned short hard_header_len; /* hardware hdr length */
unsigned char dev_addr[MAX_ADDR_LEN];
unsigned char addr_len; /* hardware address length*/
unsigned char broadcast[MAX_ADDR_LEN];
unsigned int promiscuity;
…
57. struct net_device{
…
unsigned mtu; /* interface MTU value */
unsigned short type; /* interface hardware type */
unsigned short hard_header_len; /* hardware hdr length */
unsigned char dev_addr[MAX_ADDR_LEN];
unsigned char addr_len; /* hardware address length */
unsigned char broadcast[MAX_ADDR_LEN];
unsigned int promiscuity;
…
58. struct net_device{
…
unsigned mtu; /* interface MTU value */
unsigned short type; /* interface hardware type */
unsigned short hard_header_len; /* hardware hdr length */
unsigned char dev_addr[MAX_ADDR_LEN];
unsigned char addr_len; /* hardware address length */
unsigned char broadcast[MAX_ADDR_LEN];
unsigned int promiscuity;
…
61. We don’t process the packet in the interrupt subroutine.
Netif_rx() – raise the net Rx softIRQ.
Net_rx_action() is called - start processing the packet
Processing of packet starts with the protocol switching section
62. Netif_receive_skb() is called to process the packet and find out the next protocol layer.
Protocol family of the packet is extracted from the link layer header.
63. ip_rcv() is an entry point for IP packets processing.
Checks if the packet we have is destined for some other host (using PACKET_OTHERHOST)
Check the checksum of the packet by calling ip_fast_csum()
64. Call ip_route_input() , this routine checks kernel routing table rt_hash_table.
If packet needs to be forwarded input routine is ip_forward()
Otherwise ip_local_deliver()
ip_send() is called to check if the packet needs to be fragmented
If yes , fragment the packet by calling ip_fragment()
Packet output path – ip_finish_output()
ip_local_deliver() – packets need to delivered locally
65. ip_defrag()
Protocol identifier field skb->np.iph->protocol (in IP header).
ForTCP, we find the receive handler as tcp_v4_rcv() (entry point for theTCP layer)
66. _tcp_v4_lookup() – find the socket to which the packet belongs
Establised sockets are maintained in the hash table tcp_ehash.
Established socket not found – New connection request for any listening socket
Search for listening socket – tcp_v4_lookup_listener()
tcp_rcv_established()
67. Application read the data from the receive queue if it issues recv()
Kernel routine to read data fromTCP socket is tcp_recvmsg()